#define _CRT_SECURE_NO_WARNINGS 1
#include<bits/stdc++.h>
using namespace std;
#define pi 3.141592653589793238462643383279502884197169
using ll = long long;

int main() {
    int a, b; scanf("%d%d", &a, &b);
    printf("%.10lf\n", pi * (a + b) * (a + b));
    return 0;
}